LATERAL N-I-P-I SUPERLATTICES IN SI METAL-OXIDE-SEMICONDUCTOR STRUCTURES

A stacked-gate technique is used to realize a large lateral potential modulation in microstructured silicon metal-oxide-semiconductor samples, thus making possible the search for closely spaced alternating quasi-one-dimensional channels of electrons and holes. Far-infrared transmission spectra measured at liquid-helium temperature show, besides the well-known absorption in electron quantum wires, an additional signal due to one-dimensional hole channels. With appropriate gate voltages applied to the top and bottom gate the transition from a two-dimensional hole system and a two-dimensional electron system to a so-called lateral n-i-p-i superlattice is investigated in magnetic fields up to 15 T. © 1995 The American Physical Society.